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本期刊登了黄志诚和刘冠邦有关太湖“溅射物”的讨论文章。该文从沉积学观点,对太湖某些沉积物及结核开展了
研究工作,确定了沉积成因菱铁矿结核的存在, 并据此对我们在2009 年提出的太湖“溅射物”冲击成因观点提出质疑。这
些非溅射物结核的新资料,为进一步深入对比研究溅射物提供了某些参考。本文根据溅射物的外形、内部特征以及同位素
资料,与非溅射物结核进行了初步对比,结果显示对太湖“溅射物”的不同结论可能与研究样品差异有关, 相关研究工作
还值得进一步深入下去。 相似文献
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With rising public awareness of climate change, celebrities have become an increasingly important community of non nation-state ‘actors’ influencing discourse and action, thereby comprising an emergent climate science-policy-celebrity complex. Some feel that these amplified and prominent voices contribute to greater public understanding of climate change science, as well as potentially catalyze climate policy cooperation. However, critics posit that increased involvement from the entertainment industry has not served to influence substantive long-term advancements in these arenas; rather, it has instead reduced the politics of climate change to the domain of fashion and fad, devoid of political and public saliency. Through tracking media coverage in Australia, Canada, the United States, and United Kingdom, we map out the terrain of a ‘Politicized Celebrity System’ in attempts to cut through dualistic characterizations of celebrity involvement in politics. We develop a classification system of the various types of climate change celebrity activities, and situate movements in contemporary consumer- and spectacle-driven carbon-based society. Through these analyses, we place dynamic and contested interactions in a spatially and temporally-sensitive ‘Cultural Circuits of Climate Change Celebrities’ model. In so doing, first we explore how these newly ‘authorized’ speakers and ‘experts’ might open up spaces in the public sphere and the science/policy nexus through ‘celebritization’ effects. Second, we examine how the celebrity as the ‘heroic individual’ seeking ‘conspicuous redemption’ may focus climate change actions through individualist frames. Overall, this paper explores potential promises, pitfalls and contradictions of this increasingly entrenched set of ‘agents’ in the cultural politics of climate change. Thus, as a form of climate change action, we consider whether it is more effective to ‘plant’ celebrities instead of trees. 相似文献
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Under neoliberal schemes like audit systems, consumer demands born of concerns about food safety, the environment and animal welfare are theoretically poised to influence agricultural production systems (Campbell and Le Heron, 2007). Whether such influences might reverse or redirect the trend toward environmentally-damaging rampant productivism of the 20th century hinges in part on the subjective positions of farmers and the ways in which they inform how farmers respond to policy and market signals.In this paper we argue the need for a genuine engagement with both the complexities of farmer subjectivity and the interactions amongst farmer subjectivity and agro-ecologies, and animal bodies in particular. This paper presents a case study of sheep farmers on the South Island that reveals contestation and transitions in traditional markers of “good farming”, particularly animal health. We observe how such transitions arise from reconfigurations of the relationships between agro-ecological, political and social histories. In this paper’s formulation, neither state subsidies nor neoliberalism in agriculture is primary cause or ultimate effect of the transformation of agricultural practice. Rather, changes in the political economy expose contradictions in farmer subjectivities, the resolution of which may block or reinforce trends suggested by the political economy. We suggest that contested ideas about animal health within the social field of pastoral farming in New Zealand makes it possible that New Zealand’s sheep growers may take the high road of best environmental practice via highly audited environmental standards of production demanded by elite consumer markets, or that they may remain in the intensifying trajectory of continuing to drive the sheep’s body to its maximum possible intensity of production. The mixed legacy of neoliberal reform is that it has simultaneously enabled both of these contradictory trajectories in New Zealand pastoralism. 相似文献
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首先,非常感谢朱建明副教授对笔者撰写的发表于《岩土力学》2012年第33卷第10期的论文《基于土拱效应原理求解挡土墙被动土压力》[1]（以下简称原文）的关注,同时非常感谢《岩土力学》编辑部给予笔者这样一个很好的学术交流平台。现针对讨论稿提出的问题做出以下答复：
1滑裂面倾角是否合适
讨论稿中提到,当时,按照原文公式计算会得到滑裂面倾角?趋近于90°,与实际情况不符合。但按照原文的计算假设条件来看的情况是略有不同的,根据计算可知,墙土间的外摩擦角?是土拱效应存在的前提条件,其值与墙背面的摩擦情况和排水条件有关,根据《水工挡土墙设计规范》表 A.0.1[2],外摩擦角?与内摩擦角?的比值范围如表1。 相似文献
1滑裂面倾角是否合适
讨论稿中提到,当时,按照原文公式计算会得到滑裂面倾角?趋近于90°,与实际情况不符合。但按照原文的计算假设条件来看的情况是略有不同的,根据计算可知,墙土间的外摩擦角?是土拱效应存在的前提条件,其值与墙背面的摩擦情况和排水条件有关,根据《水工挡土墙设计规范》表 A.0.1[2],外摩擦角?与内摩擦角?的比值范围如表1。 相似文献
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It is increasingly argued that we are entering into a “biotech century”, in which biotechnology promises major advances in agricultural productivity. The development of biotechnology is not a straightforward affair, however, and the advent of GMOs has led to public protest and consumer resistance. This paper draws upon a comparative Australian-UK project concerned with the role of regulation and governance in mediating the debates and managing the associated risks. Regulatory responses and the mediation of conflicts by the Australian and UK governments have been shaped by the institutional and policy environments in these two countries. The implications of these public debates and regulatory responses for the capture of competitive opportunities are considered. The fact that the two countries have broadly similar systems of governance and regulation reveals how alike the circumstances are in many respects. But at the same time there are important differences in both the style and the content of the policy debates. In both the UK and Australia, the respective central governments remain committed to a ‘biotechnology future’. Against this background, there is little doubt that the choices about biotechnology will play a defining role in shaping the future of rural places. 相似文献
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This paper explores the lived experiences and aspirational social constructions of call centre work and employment in India’s high profile IT Enabled Services-Business Process Outsourcing (ITES-BPO) industry; the ways in which they differ from those previously documented amongst call centre workers in the Global North (specifically the UK); and the consequences of that geographical reconfiguration of offshored call centre work for the replicability in India of workplace collective bargaining strategies successfully developed in some UK call centres. These issues are analysed using new empirical evidence from a regional survey of 511 non-unionised ITES-BPO workers and 42 in-depth interviews in India’s National Capital Region. Based on this analysis, the paper then discusses the operation, outcomes and ongoing challenges faced by the newly formed ‘Union for ITES Professionals’ (UNITES Pro) in developing an alternative occupational organising model better suited to the particular needs, motivations and preferences of India’s young, mobile, call centre workers. The empirical analysis presented in the paper is located, therefore, within wider debates on the role of geographical context in shaping possibilities for organising white-collar service workers at different ends of global service chains in the new economy. 相似文献
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This paper explores the relationship between interdisciplinary studies and research and researchers’ positionalities, both within and beyond geography. The profound degree to which researchers’ assumptions, expectations and attitudes (which in turn are affected by their personal backgrounds, training, location, etc.) influences the very notion of interdisciplinarity, and what it involves and consists of, is often neither noted nor appreciated. This paper will illustrate, particularly through personal examples, how positionality is part of the circuit of knowledge production, informing academic research, employment and publishing to no small extent. The boundaries of interdisciplinary research are shown to be under constant negotiation, still far from mutual understanding or consensus, a fact which explains the often uneasy identification and negotiation of oneself as an interdisciplinary scholar. The paper concludes by making recommendations at individual and institutional level on how to overcome some of the constraints imposed by researchers’ positionalities to the promotion of interdisciplinary research. 相似文献
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Estimation or simulation? That is the question 总被引：1，自引：0，他引：1
Jorge Kazuo Yamamoto 《Computational Geosciences》2008,12(4):573-591
The issue of smoothing in kriging has been addressed either by estimation or simulation. The solution via estimation calls
for postprocessing kriging estimates in order to correct the smoothing effect. Stochastic simulation provides equiprobable
images presenting no smoothing and reproducing the covariance model. Consequently, these images reproduce both the sample
histogram and the sample semivariogram. However, there is still a problem, which is the lack of local accuracy of simulated
images. In this paper, a postprocessing algorithm for correcting the smoothing effect of ordinary kriging estimates is compared
with sequential Gaussian simulation realizations. Based on samples drawn from exhaustive data sets, the postprocessing algorithm
is shown to be superior to any individual simulation realization yet, at the expense of providing one deterministic estimate
of the random function. 相似文献
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《Geoforum》2018
The ‘just transition’ is a concept receiving more attention in the literature to-date. This critical review discusses this and how there are overlaps with literature on energy, environmental and climate justice. Within the separate energy, environment and climate change scholar communities, there is too much distortion of what the ‘transition’ means and what ‘justice’ means, and they all should be understood within the just transition concept. To increase public understanding and public acceptance of a just transition, these research communities need to unite rather than continue alone. 相似文献
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《Earth》2003,60(1-2):131-146
This review paper is mainly concerned with a geochemical investigation of the deepest part of the Vostok ice core between 3310 m, the depth at which the palaeoenvironmental record present in the ice above is lost, and the bottom of the core about 130 m above subglacial Lake Vostok. Two sections constitute this part of the core.The upper section (3310–3539 m depth) still consists of ice of meteoric origin but subjected to widespread complex deformation. This deformation is analysed in light of a δD–deuterium excess diagram and information on microparticles, crystal sizes and chemical elements distributions in that part of the core. Such ice deformation occurred when the ice was still grounded upstream from Vostok station in a region with subfreezing temperatures.The lower section from 3539 m to the bottom of the core at 3623 m depth is lake ice formed by freezing of subglacial Lake Vostok waters. This is indicated by the isotopic properties (δD, δ18O and deuterium excess), by electrical conductivity measurements (ECM), crystallography and gas content of the ice. These ice core data together with data on ionic chemistry favour an origin of the lake ice by frazil ice generation in a supercooled (below pressure melting point) water plume existing in the lake followed by accretion and consolidation by subsequent freezing of the host water.The helium profile of this deepest part of the Vostok core is quite unusual and surprising. It has important implications for the interactions between the ice sheet and the lake. Two constrasting scenarios can be satisfactorily constructed so that the lake residence time is not well constrained. 相似文献
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《Sedimentology》2018,65(4):1301-1321
Aeolian dune fields evolve from protodunes and small dunes into a pattern of progressively fewer, larger and more widely spaced dunes within limits defined by boundary conditions. However, the allogenic boundary conditions that promote aeolian dune‐field development, accumulation of strata and preservation of accumulated strata are not the same. Autogenic processes, such as dune interactions, scour‐depth variation along migrating dunes and substrate cannibalization by growing dunes, result in removal of the stratigraphic record. Moreover, dune‐field events may be collapsed into major erosional bounding surfaces. The question is what stages of evolving dune fields are represented in the rock record? This case study of ca 60 m of Jurassic Entrada Sandstone on the Utah/Arizona border (USA) defines stratigraphic intervals by gross architecture of bounding surfaces and sets of cross‐strata. The interpreted intervals in stratigraphic order consist of: (i) a lower sabkha bed that transitions upward into erosional remnants of small sets representing an initial wet aeolian system; (ii) large, compound cross‐strata representing a mature dune field; (iii) isolated scour‐fill representing negatively climbing dunes that produced ca 25 m of palaeo‐topographic relief; (iv) downlapping sets that fill the landscape‐scale relief; (v) four intervals of stacked climbing sets that each represent short periods of time; and (vi) an upper sabkha bed that again transitions into small sets representing a wet system. Accumulations appear to be associated with sediment pulses, a rising water table, and filling of scoured troughs and landscape‐scale depressions. Preservation of the accumulations is selective and associated with a rising water table, burial and subsidence. The preserved record appears remarkably incomplete. Speculation about missing strata gravitates towards cannibalization of the record of early dune‐field construction, and strata removed during the formation of bounding surfaces. This local Entrada record is thought to represent a point in the spectrum of preservation styles in the rock record. 相似文献
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On and Off the North China Craton: Where is the Archaean Keel? 总被引：67，自引：2，他引：65
FAN W. M.; ZHANG H. F.; BAKER J.; JARVIS K. E.; MASON P. R. D.; MENZIES M. A. 《Journal of Petrology》2000,41(7):933-950
Geophysical data indicate that the lithosphere beneath the NorthChina Craton (NCC) is 相似文献
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The current study sought to offer guidance for developing effective web-based mapping tools for wildfire warnings by identifying (1) the important content for facilitating individuals’ decision-making, and (2) the optimal interface design for ensuring usability and ease of information access. A map-based warning tool was prototyped in the Australian context, followed by a usability and effectiveness evaluation through individual interviews and verbal protocol analysis to assess participants’ interaction with the mapping interface and information in response to the simulated warning scenario. The results demonstrated variations in participants’ approaches to wildfire warning response, revealing varied information needs. Specifically, most participants relied on their own assessment of the prospective threat, requiring specific wildfire-related information before eliciting a response. In contrast, the decision of a minority of the participants was motivated by response guidance from agencies, and accurate wildfire information was less important for their response. Imperative information for both types of residents therefore needs to be highlighted in a map-based warning tool to cater to a wide audience. Furthermore, a number of heuristics were identified for designing effective interactive functions to facilitate the control of, and access to, the various maps and textual information presented on the map-based warning interface. 相似文献
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Jiménez Martínez Maribel Jiménez Martínez Mónica Romero-Jarén Rocío 《Natural Hazards》2020,104(2):1481-1533
Natural disasters are one of the main channels through which ecological and socio-economic systems interact. In particular, the severe impacts of earthquakes could disrupt activities in the labour market. However, the literature barely researched the long-term effects of such events. To investigate this issue, this article is concentrated in Chile that is subject to recurring seismic movements. The 27 February 2010 Bío-Bío Chile earthquake (Mw 8.8) was the second strongest in the history of the country. This natural disaster can be used to evaluate the response of the labour market to an exogenous shock. Besides, the capacity for resilience in the labour market is crucial for people who rely on their job. This document analyses the impacts of the 2010 Bío-Bío earthquake and tsunami on Chilean labour market outcomes, in particular, the quality of employment. With this objective, different data are combined for analysing the effect in the short and long term. Also, distinct econometric techniques and exogenous measurements of seismic acceleration are used. The evidence shows that these catastrophes harmed the labour market in the short term. However, in the long term, the government’s reconstruction efforts and other factors could have attenuated the adverse effects over some variables in the most affected zones.
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The Thiem equation of radial groundwater flow to a well is more than 100 years old and is still commonly used. Here, deviations caused by some of its simplifications are quantified by comparing the analytical to a numerical model that allows the implementation of more complex geometries. The assumption of horizontal flow in the Thiem equation, which necessitates uniform inflow over the entire screen length of the fully penetrating well, was found to cause deviations from actual pumping wells where the pump is placed above the screen, resulting in non-uniform inflow and additional drawdown. The same applies to partially penetrating wells, where inflow peaks and additional drawdown occur, especially when the well is screened in the lower part of the aquifer. The use of the Thiem equation in the near-field of a well should thus be restricted to situations where the screen inflow is relatively uniformly distributed, e.g. when it covers large portions of the aquifer thickness. The presence of a gravel pack and a background gradient, on the other hand, are of limited importance. 相似文献